The United States and Japan will step up their defence cooperation to deal with the threat from nuclear-armed North Korea as tensions in East Asia remain high, officials from the two allies said on Thursday.

People smuggler jailed for 11 years

An Iraqi refugee turned people smuggler operated like an "attentive travel agent" and was motivated by profit, a judge says.

Victorian County Court Chief Judge Michael Rozenes sentenced Ali Haidari to 11 and a half years in prison for arranging travel for asylum seekers from Iran to Indonesia where they boarded boats for Australia.

Iraq-born Haidari had pleaded guilty to three people-smuggling charges and one drug importation charge.

Judge Rozenes said the Kurdish refugee had had a difficult life, fleeing to Iran as a child before leaving in 2000 to seek asylum in Australia, where he was granted citizenship in 2007.

But while Haidari empathised with asylum seekers, he was still motivated by profit, the judge said.

"Your role could be described as that of a very attentive travel agent," Judge Rozenes said.

"Whilst it is possible that you were partially motivated by genuine altruistic humanitarian concerns, having regard to your own experience, your actions were nevertheless highly unlawful.

Haidari accepted $US8000 ($A7667) from an Iranian man in 2009 for a boat journey to Australia and a year later was paid by two Kurdish families for similar voyages before he was caught selling tickets in a sting operation last year.

He also made arrangements to receive 629 grams of crystal amphetamine, with a street value of up to $5 million, which was intercepted.

The judge said Haidari had pursued refugees for additional money after they arrived in Australia and had misled them about the provision of lifeboats.